Brain activation and heart rate during script-driven traumatic imagery in PTSD: preliminary findings

Patients with posttraumatic stress disorder (PTSD) experience psychological and physiological distress. However, imaging research has mostly focused on the psychological aspects of the disorder. Considered an expression of distress, heart rate (HR) in PTSD is often elevated. In the current study, we sought to identify brain regions associated with increased HR in PTSD. Nine patients with PTSD and six healthy trauma survivors were scanned while resting, clenching teeth, and listening to neutral and traumatic scripts. Brain function was evaluated using H2O15 positron emission tomography (PET). HR was monitored by electrocardiogram. Data were analyzed using statistical parametric mapping (SPM). Subjects with PTSD exhibited a significant increase in HR upon exposure to traumatic scripts, while trauma survivors did not. Correlations between regional cerebral blood flow and HR were found only in patients with PTSD, in orbitofrontal, precentral and occipital regions. Neither group showed correlation between rCBF and HR in the amygdala or hippocampus. These preliminary results indicate that "top down" central nervous system regulation of autonomic stress response in PTSD may involve associative, sensory and motor areas in addition to regions commonly implicated in fear conditioning.